1. Field of the Invention
The present invention relates generally to fluid flow sensing apparatus and more particularly to a flow splitting device which accurately separates a splitstream that is linearly related to the total flow stream being monitored and is substantially independent of flow stream variables.
2. Description of the Prior Art
In the processing of electronic components, as well as in many other processing fields utilizing a stream of flowing fluid in either gaseous or liquid form, it is necessary that one be able to accurately measure the quantity of fluid flowing through a supply conduit and into a particular utilization chamber or the like. It is also important to know that the indication remains accurate with changes in fluid pressure, temperatures, viscosity or molecular weight.
Although numerous types of fluid flow meters are described in the prior art, among which are included those devices disclosed in the U.S. patents to E. T. Booth, Jr., U.S. Pat. No. 2,594,618, Frank D. Werner, et al., U.S. Pat. No. 3,433,068 and Richard F. Blair, U.S. Pat. No. 3,938,384, the accuracy of such devices with respect to changes in fluids and the variable parameters thereof is dependent upon the use of electronic or other compensating means in order to provide appropriate compensation for the nonlinearity of the flow division.
The principal problem associated with prior art devices is that the flow dividing systems typically do not provide a linear relationship between the main body of the flow and the portion of the flow which is directed through a sensing element. As a consequence, where the split flow is not linearly related to the main flow, the sensed output will necessarily be nonlinear and the nonlinearity must be compensated for.